DESCRIPTION: Physical Sciences Inc. (PSI) proposes to partner with clinicians in the Harvard Department of Oral and Maxillofacial Surgery to develop an innovative device for distraction osteogenesis (DO) of the mandible. DO taps the bone regeneration ability of the body to fill a bone gap that is gradually expanded with a mechanical distractor. The concept proposed will use miniature hydraulics to produce a fully buried actuator capable of producing curved distraction trajectories. The device will allow skeletal expansion without linkages that pass through the skin, reduce patient responsibility by automating the motion process, permit clinicians to alter the distraction trajectory as treatment progresses, and reduce distraction time by making the motion nearly continuous. The program will emphasize the ability to make curvilinear distraction trajectories. Several key engineering innovations will make the new distractor possible. These include: micro- and miniature valve technologies, storage of hydraulic energy, a low-power RF link for in vivo programming and control, and multi-actuator design for complex trajectories. In Phase I, PSI will identify solutions to critical technology challenges, build a prototype device, and demonstrate feasibility by implanting it in a porcine cadaver. The Phase II program will include constructing a complete buried distraction system and testing in a live animal.